Recently, applications which use peer-to-peer (P2P) communications without any particular server have been drawing attention even on large networks such as the Internet. Typically, this type of applications include music-content exchange tools such as Napster and Gnutella and various communications tools such as instant messengers.
Also, network connections are now available to PDAs (Personal Digital Assistants, cellular phones, and other portable terminals. Such communications can take various forms, including local communications by means of short-distance wireless communications or infra-red light, indirect Internet connections via telephone company lines, etc.
Communications by means of portable terminals are advantageous in that they allow users to conduct communications and exchange data from anywhere. With the spread of a communications method which allows portable terminals to conduct peer-to-peer communications with each other directly (without a server) and exchange or deliver digital content (hereinafter referred to simply as content) by running an application with peer-to-peer communications capabilities on the portable terminals, it is expected that full-fledged commercial activities will be implemented using this as a platform.
Incidentally, methods of connecting to a network via a portable terminal generally have the following disadvantages because they employ wireless as well as hardware configuration that attaches importance to portability:                relatively unstable communications channels due to the use of wireless;        lower communications speed than wire communication;        lower data storage capacity than information equipment such as personal computers;        lower processing capability than information equipment such as personal computers;        inferior output devices (screen, etc.) compared to those of information equipment such as personal computers; and        necessity to minimize power consumption due to predominant use of battery power (including reduction of power consumption for network connection).        
The communications speed, data storage capacity, processing capability, etc. are expected to be improved with advances in technology. However, there are definite differences in capability from a wired network connection between a personal computer or the like and a network.
In commercial activities using network connections based on above described portable terminals, it will be necessary to take the following points into consideration.                It is necessary to transmit content, request transmission of content, etc. on a portable terminal.        It is likely that higher-quality content or higher-priced content than the content currently transferred between portable terminals will become available. In that case, the volumes of main data transmitted and received will generally be fairly large.        When content is traded, it is necessary to clarify its ownership. Generally, it is considered that a user's ownership of content is established at the moment when transfer of the content from the remote end to the user is completed.        
However, methods of connecting wirelessly to a network from a portable terminal present the following problems because such methods of connection have the disadvantages described above.                A network connection should be maintained for a long time to transfer a large volume of data. For example, when transferring data via local communication, a connection should be maintained until the communication is completed. This wastes time and battery life.        If it is considered, as described above, that a user's ownership of content is established at the moment when transfer of content from the remote end to the user is completed, the user cannot own data if communication is interrupted halfway through transfer of the data. In the case of unstable wireless communications, such a situation can occur frequently. Also, retransmission of data and other processes will complicate the situation if the communications channel is unstable. Thus, it takes a lot of time and labor to establish the “ownership” of the data.        Portable terminals, whose output device is not provided with high functionality, are not necessarily intended to use high quality data. In other words, although high-quality, high-priced content is expected to be exchanged when commercial activities using portable terminals are implemented, in many cases, the portable terminals themselves are not suitable for utilizing such content directly.        
Thus, with network connections using current portable terminals, it is difficult to meet the needs to:                exchange large volumes of data efficiently;        determine content and acquisition methods of data exchanged between portable terminals through peer-to-peer communications;        eliminate the need for portable terminals to maintain a network connection for a long time; and        output only properly processed data to a portable terminal while a large volume of data is received.        